1016 lines
50 KiB
Plaintext
1016 lines
50 KiB
Plaintext
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* PERFECT BOX *
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Loudspeaker Enclosure Simulation
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using the
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Neville Thiele - Richard Small Model
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Version 4.5
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January 1, 1990
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Warren A. Merkel
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2851 Newcomb Ct.
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Orlando, FL 32826
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Program registration is required.
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See final page of this document for details.
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***** PERFECT BOX ***** Version 4.5 ******
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* Program and documentation written by *
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* Warren A. Merkel *
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******************************************
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I. INTRODUCTION:
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PERFECT BOX is a Computer Aided Design (CAD) program for the
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simulation of loudspeaker performance. PERFECT BOX is a very
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powerful tool for the amateur or professional speaker builder.
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Loudspeaker design is a balance of compromises involving
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enclosure size, low frequency cutoff, and transient response.
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This program will allow you to model the loudspeaker-enclosure
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combination entirely on your PC. With proper use, you can be
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assured of the best (lowest in frequency) bass response in the
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smallest enclosure. You can then build the enclosure with full
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confidence that the final result will not become the new dog
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house for Fido, but an accurate, natural sounding system.
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PERFECT BOX does not deal with midrange or tweeter drivers. It
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only considers the low frequency driver in a multi-way system (or
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the only driver in a full-range system.) Since enclosure
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alignments, such as box size, box type, and box frequency (now on
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referred to as Alignments), effect the woofer response, PERFECT
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BOX models systems covering low frequencies from 10 to 200 Hertz.
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The mathematical model will hold for higher frequencies, but I
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have optimized the program for the most useful range.
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II. REQUIREMENTS:
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PERFECT BOX requires certain parameters that uniquely define the
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driver's characteristics. Some of these parameters have been
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coined as the Thiele/Small (or T/S) parameters. If you are new
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to loudspeaker design, it isn't important that you understand
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what each value represents, only that you are able to obtain
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these values from the driver manufacturer, or measure them
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yourself (the preferred method.)
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PARAMETER UNITS
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Free air resonance (Fs) Hertz
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Electrical (Qes)
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Q Mechanical (Qms)
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Q Total (Qts)
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Volume Equivalent Compliance(Vas) Ft^3
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D.C. Voice Coil Resistance (Re) Ohms
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Peak Cone Displacement (Xmax) Inch
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Effective Piston Diameter Inch
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Thermal Power (P) Watts, RMS
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PERFECT BOX allows you to store these driver parameters in a data
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file ("BOXDATA4"). This file can store characteristics for
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thousands of different drivers. A few sample drivers have been
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included so that you can experiment with PERFECT BOX. These
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samples represent "real life" units which are currently available
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at this time.
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III. DEFINITIONS:
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***SYSTEM ORDER***
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PERFECT BOX uses a classical high-pass filter model to simulate a
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loudspeaker mounted in an enclosure. The order of a loudspeaker
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system represents the same characteristic roll off as that of an
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electrical filter. The roll off rate (or slope) is:
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roll off rate = (6 * system order) dB/frequency octave
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or roll off rate = (20 * system order) dB/frequency decade.
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PERFECT BOX can simulate both infinite baffle (sealed box), and
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vented (ported) systems. Each of these systems have a natural
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order in which they resemble an electrical high pass circuit.
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For infinite baffle, order=2, or that is to say that they are of
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2nd order. And for vented systems, order=4. It seems that each
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kind of enclosure has pros and cons associated with them.
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In general, both systems, if properly aligned, perform with the
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same low frequency response. In practice, an infinite baffle
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system is easier to build, and possibly has better transient
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response. The vented system offers slightly higher efficiency
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(2.9 dB), and good cone dampening near the vent frequency (but
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less below Fb.) My preference is for 4th and 6th order systems.
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The sixth order system involves the use of a 4th order system
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tuned slightly lower than the 4th order ideal, and an 2nd order
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active equalizer circuit in the amplifier path.
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***SYSTEM CUTOFF FREQUENCY***
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This is the frequency at which the system amplitude response is
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exactly 3.0 dB less than at a mid-band reference frequency (where
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response is basically flat at 0 dB.) This is a standard point of
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interest that can be used to compare with another system's low
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frequency response data. This point on the frequency plot
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represents the "half-power" amplitude, as compared to the
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amplitude at a mid-band reference frequency.
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***OTHER SYSTEM ORDERS***
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As you are probably aware, a Graphic Equalizer can make a
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tremendous effect on the way your speaker system sounds. The
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bad news is that an equalizer (EQ) usually doesn't have a control
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exactly centered on the proper frequency to properly extend low
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frequency cutoff, and thus will typically make matters worst.
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PERFECT BOX can incorporate the effects of either a 1st or
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2nd order, ACTIVE EQ (that you must build) into the loudspeaker
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model. The affects of which are easily depicted in the PB Graphic
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Plots.
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This mini EQ consists of a simple active high-pass filter, having
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a low turn-over (cutoff) frequency (typically 20-60 Hz), which
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actually has a slight boost (peak) in its amplitude response
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above its cutoff frequency. If the amount of boost and cutoff
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frequency are suitably chosen, the total system response
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typically is extended a half-octave or more, while
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providing infrasonic (rumble) filtering to boot. In
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2nd-order EQ's, the boost is controlled by the "D" parameter
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(D=1/filter Q, for you filter buffs.) Typical values of
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"D" range from 0.3 to 1.414, giving most to least amount of
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amplitude boost. A "D" of 0.52 gives approximately 6 dB of
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boost, a typical starting value. The EQ frequency and the
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"D" factor should be juggled for the flattest, most extended low
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frequency response. Use the "EQ2.EXE" program to calculate
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components to implement the 2nd order EQ.
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A word of caution. Using large amounts of boost may tax small
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power amplifiers (less than 50 Watts,RMS) beyond their
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limits. A properly designed 3, 3.5, 5, or 6th order system will
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not over tax your amplifier unless you listen to music either :
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1. at extremely high SPL levels,
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2. with heavy (double fortissimo) organ pedal notes, or
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3. use other signal modification equipment such as an
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extremely low-end boosted Graphic Equalizer
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(quite stupid!), or Sub-Sonic Synthesizer (Harmonizer.)
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The EQ can be inserted into the signal path of your system at
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either a "Preamp-out/Amp-in" loop, or "tape monitor" connection.
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A simple design for a 2nd order EQ is provided with PERFECT BOX.
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Type EQ2 at the DOS prompt to execute this option. You must
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have (at least) a CGA graphics card in order to run EQ2 because
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the electrical schematic is drawn on the screen after all of the
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circuit values are calculated.
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IV. RUNNING PERFECT BOX - PROGRAM EXECUTION:
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If you have an IBM, Epson or HP LaserJet compatible printer,
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you can print the graphic plots generated by PERFECT BOX. Perfect
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Box 4.5 has built-in support for Graphic printing for these
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printers in CGA and EGA modes. You no longer have to use
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the DOS GRAPHICS.COM or PERFGRAF.COM included with previous
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releases of Perfect Box. You might have to set your printer
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switches to DEFEAT "automatic" Linefeed [LF] after a Carriage
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Return [CR], (see your printer manual.)
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I have included a simple batch file called GO.BAT,
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which will execute Perfect Box for you. You may change this
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batch file to suit your particular needs. The actual program
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file is BOX4_5.EXE. You will not have to change the program
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file name until you receive a future upgrade of PERFECT BOX.
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Insert the PERFECT BOX program disk into your default disk
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drive, and type GO <Return>. You should see the PERFECT BOX
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opening screen. Take the time to read this screen and remember
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that many, many hundreds of hours of effort have been put into
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this program. If you use this program more than five times, you
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must be understanding the purpose so don't forget your obligation
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to this author!
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If you see an error message stating "Bad Command or
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Filename", check to see if you are in the same directory as the
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PERFECT BOX files. After about 5 seconds, you may press RETURN
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to continue.
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If all is well, you should see the following screen.
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PERFECT BOX - Version 4.5 Current Time:
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<20> Boxdata Choices <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ
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<20> <20> <20> Drivers on file : 1573 <20>
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<20> (B) Browse the database <20> <20> Boxdata path : G:\perfect\ <20>
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<20> (L) Load a driver by # <20> <20> Graphics mode : EGA <20>
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<20> (S) Store New Driver data <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
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<20> (E) Edit the database <20> Quick Mode
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<20> (B) Boxdata Reports <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Utility <20>ͻ
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<20> <20> <20>
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<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> (C) Change Boxdata path <20>
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<20> (P) Sort/Pack Boxdata file <20>
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<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ <20> (A) Append new records <20>
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<20> REGISTERED TO: <20> <20> (W) Write defaults <20>
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<20> Trial copy. <20> <20> (D) DOS Shell <20>
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<20> Your name or <20> <20> (Q) Quit to DOS <20>
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<20> company name should<6C> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
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<20> be listed here. <20>
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<20> <20>
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<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
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Use PgUp - PgDn - Home - End - - - <RETURN>= Select - or HotKey
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Output Menu
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Each of the menu choices may be executed by either pressing the
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"key letter" or by using the cursor arrow keys to highlight the
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choice and then pressing RETURN. If you have a mouse, you can
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choose by clicking the left button on any of the options
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BOXDATA CHOICES:
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(B) Browse. This option will allow you to view the drivers
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currently in the BOXDATA file. You can move through the list
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using the arrow, Home, End, Page Up, and Page Down Keys. The end
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key takes you to the bottom of the list, and Home will return you
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to the first listing. Use these keys to point the "flashing
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arrows" at your driver choice. If you have sorted your Boxdata
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file using the Sort/Pack option, you can press any of the Alpha
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keys (A-Z) to jump to that corresponding Manufacturer name. If
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you have a mouse installed, you can move the highlight arrows
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straight to the driver of interest with the left button. The
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right button will load the currently selected line.
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Browse-Choose the driver with the arrow keys and press RETURN.
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<20>106 <20>PR 38 XM 150 <20>POLYDAX <20>15",PRO,MONITOR,96dB <20>
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107 PR 38 XT 150 POLYDAX 15",PRO,FOAM EDGE,MONITOR
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108 PR 38 XT 250 POLYDAX 15",PRO,99dB
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109 PR 38 XT 350 POLYDAX 15",PRO,HI-POWER,100dB
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110 TA-305 FSW PRECISION DUAL V.C. SUBWOOFER
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111 TA-305F PRECISION OMEGA
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112 TD-125F PRECISION ALPHA
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113 TD-255F PRECISION EPSILON
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114 TD-255F-SW PRECISION 10",Alum Dual VC,90.7dB
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115 TO-205F PRECISION INFINITE BAFFLE 8"
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(** Only ten drivers are listed here for clarity. **)
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<Esc>=Quit - <F2>=Edit - <F3>=Load defaults.
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PgUp-PgDn-Home-End - <INS>=Get # < <<3C> >= Get Record 106
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Perfect Box Browse function.
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After pointing to a particular driver, you may LOAD the driver
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parameters by pressing RETURN. You can EDIT the driver
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parameters by pressing the <F2> function key. The <F3> function
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key will load any previous Box Volume, Vent Frequency, Order, D
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factor, and EQ frequency information saved in a previous
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execution of PERFECT BOX, and initiate the calculation loop. You
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still can bypass the current selected driver and load any other
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driver by pressing <INSERT> and entering the record number. The
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<F3> function key will take you back out to the opening menu.
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When you return to the BROWSE function, the BOXDATA list will be
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on the same page as the last time you were there.
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(L) LOAD:
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This option allows you to LOAD driver data directly from the
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BOXDATA file using the record number. On Floppy based systems,
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this option might save you time by skipping the Browse feature.
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(S) STORE:
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This option allows you to enter new driver data into the
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BOXDATA file. ALL parameters listed are required, so don't skip
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any unless you are told you may enter a Zero. If you don't have
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all of the correct T/S parameters, you should try to obtain them
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from the manufacturer. In a pinch, you can approximate values
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from other drivers in the BOXDATA file. Don't forget to add the
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correct values when you get them. Of course, the accuracy of
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this loudspeaker model is DIRECTLY proportional to the T/S
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parameter accuracy! Which brings me to say this:
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I claim no responsibility for the completeness or accuracy
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of the T/S parameters included with your copy of PERFECT
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BOX. Many (very many!) of the current drivers listed have
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been appended from files sent to me by Registered users of
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PERFECT BOX. If you are unsure of any data, it is your
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responsibility to verify the T/S parameters with
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the manufacturer or test them yourself!
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(Soapbox off.)
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The new entries are placed at the bottom of the BOXDATA file
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and once entered, can be LOADED immediately.
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(E) EDIT:
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You can edit any of the T/S parameters in the BOXDATA file. Use
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the current driver record number to call up the driver and
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follow the screen prompts for instructions. You can also edit a
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driver directly from the BROWSE function.
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(B) REPORTS:
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You can print the full BOXDATA file on your printer in two
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forms. The first form contains ALL of the driver parameters
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including comments. The second form will print the driver's
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basic T/S parameters, Fs, Vas, and Qts, and use them to calculate
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the "Ideal" 4th order Box volume, Vent frequency, and F3 cutoff
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point. This form is very handy to compare driver performance.
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UTILITY
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(C) Change Boxdata Path:
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The BOXDATA file containing all driver parameters, can be
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located on a different drive/directory than the current DOS
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default. Choose this option if you want to change the path to
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the data file. Note: The path is saved for future executions of
|
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PERFECT BOX using the Write Defaults option. You could use this
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feature to maintain more than one BOXDATA4 file.
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(P) Sort/Pack
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Each new driver that you enter into the BOXDATA file is placed
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at the bottom of the file. You can use the Sort/Pack option to
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sort the file alphabetically by Manufacturer. If you have
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marked a driver for deletion in the EDIT driver menu, the Sort /
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Pack routine will purge it from the BOXDATA file. This routine
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is the an updated version of the sort program that was included
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with earlier versions of PERFECT BOX, and thus (if you have
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them) you should delete the old BSORT.BAT and BOXSORT3.EXE
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program files.
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(A) Append new records
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This option is used to combine other BOXDATA files into the
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current, active BOXDATA file. If you are upgrading from Version
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3.xx, rename the OLD data file to "DATAUP.DAT". Start PERFECT
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BOX and choose the Append option. If you are upgrading from
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Version 2.xx, you must run the 2to4.exe program first. Version 3
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uses a slightly different file structure, and thus the 2to4.exe
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program will convert you old BOXDATA file into the new structure,
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leaving a new file called "BOXDATA4".
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Since this is the current name of the Version 4.0 data file, YOU
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MUST DO THIS CONVERSION IN ANOTHER DIRECTORY THAN THE ONE
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CONTAINING THE NEW BOXDATA4 FILE INCLUDED IN THE VERSION 4.5
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ARCHIVE! Either use a different directory or copy the NEW,
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original BOXDATA4 to another directory for safe keeping. I
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suggest that you make backup copies of EVERYTHING, OLD AND NEW,
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before attempting the conversion process. After running the
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2to4.exe program, rename the resulting file from BOXDATA4 to
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"DATAUP.DAT". Copy "DATAUP.DAT" file into the PERFECT BOX
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directory, choose the APPEND function, and watch it fly!
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(W) Write defaults.
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Each time PERFECT BOX is loaded, a file named PERFECT.CTL is read
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||
for startup defaults. There are many default values kept in
|
||
this file including: 1. Boxdata4 data file directory: 2.
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Graphics mode: CGA, EGA, or HERC; 3. "Quick mode" toggle; 4.
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Printer Port assignment, mouse calibration values and other
|
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variables.
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The first two values have obvious purposes. The third parameter
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is used to hold the default mode for the calculation loop end
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point. In normal mode, the loop counts up to 200 Hz. In Quick
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mode, the loop counts up to 100 Hz. This is useful for making
|
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quick estimates on the slower "XT" type machines. You can toggle
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this mode within PERFECT BOX with the <F9> function key. The
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write defaults option will over-write the configuration file with
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current values for BOXDATA file path, Graphics and Quick
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Modes. PERFECT BOX 4.5 uses a different format for this control
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file than earlier releases. You should delete you old
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perfect.ctl file and restart PERFECT BOX.
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(D) DOS Shell
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You can spawn another copy of COMMAND.COM from within PERFECT BOX
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using this option. Use this option to check directories or
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||
file space. Type EXIT at the DOS prompt to return to PERFECT
|
||
BOX. This option actually executes a batch file called "SH.BAT".
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||
You could modify this batch file to run another program instead
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of loading Command.com.
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(Q) Quit to DOS
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Just like it says! This choice will halt execution of PERFECT
|
||
BOX and immediately return you to the DOS.
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OK, OK!, enough talk. Let's see some action!
|
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Now that you know what all of that stuff does on the opening
|
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menu, choose a driver from the BOXDATA file. Use the BROWSE
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option, point at an interesting driver, and press RETURN. The
|
||
parameters listed are the minimum that you will need to know
|
||
about any driver simulated with PERFECT BOX. For this example,
|
||
answer "Y" to the question "Do you want this driver?" Now choose
|
||
"1" for a single driver simulation.
|
||
|
||
Record # <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>> 106
|
||
Manufacturer <20><><EFBFBD><EFBFBD><EFBFBD>> POLYDAX
|
||
Model Number <20><><EFBFBD><EFBFBD><EFBFBD>> PR 38 XM 150
|
||
Comment <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>> 15",PRO,MONITOR,96dB
|
||
Free air resonance= 19.5 hz.
|
||
Vas = 24.37 ft^3.
|
||
Qts = .27
|
||
Qes = .3
|
||
Qms = 2.7
|
||
Re = 5.8 <20>
|
||
Xmax= .1377953
|
||
Piston Diameter= 14 in.
|
||
Power= 150 Watts.
|
||
|
||
DO YOU WANT TO USE THIS DRIVER (Y)?
|
||
|
||
Now, PERFECT BOX will calculate the "Ideal" 4th Order Box volume,
|
||
the port frequency for that ideal box volume, and the cutoff
|
||
frequency (-3dB point.) The ideal box volume is the smallest
|
||
enclosure that provides the flattest, deepest low frequency
|
||
response. The cutoff point will give you a general idea of how
|
||
low the driver will perform in any box design (best case.) The
|
||
port frequency (box frequency) must be set as calculated to
|
||
obtain the cutoff predicted.
|
||
|
||
|
||
In a 4th order system: Ideal vented volume is 8.53 Ft^3.
|
||
System cut-off (-3dB) is 32.54 Hz.
|
||
If the Vent frequency is 26.61 Hz.
|
||
|
||
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ
|
||
<20> ORDER <20> SYSTEM DESCRIPTION <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||
<20> 2. <20> CLOSED BOX<4F><58><EFBFBD>without Active Equalizer <20>
|
||
<20> 3. <20> <20><>with 1st Order Active Equalizer <20>
|
||
<20> 3.5 <20> <20><>with 2nd Order Active Equalizer <20>
|
||
<20> <20> 4. <20> VENTED BOX<4F><58><EFBFBD>without Active Equalizer <20>
|
||
<20> 5. <20> <20><>with 1st Order Active Equalizer <20>
|
||
<20> 6. <20> <20><>with 2nd Order Active Equalizer <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
|
||
|
||
Efficiency Bandwidth Product..(Fs/Qes).. is 64 , which suggests a
|
||
4th order system.
|
||
Enter System Order [ 4 =default] ?
|
||
Enter BOX VOLUME (Ft^3) [ 8.53 =default] ?
|
||
Enter BOX VENT FR. (Hz.) [ 26.61 =default] ?
|
||
|
||
Now you must decide what type of enclosure to use. If the driver
|
||
has a Qts of 0.5 or greater, I would try infinite baffle
|
||
(order=2) systems first, otherwise, use Order=4, with the ideal
|
||
box size and frequency. Save the other Order options for later.
|
||
Since PERFECT BOX will recommend the Order for you, use it as a
|
||
default. Press RETURN to accept the default Order.
|
||
|
||
Enter the Box volume in cubic feet. I suggest that you use the
|
||
ideal box size as a starting point. Then, on the next pass,
|
||
change one of the box alignments and check how the response was
|
||
affected. Again, press RETURN to accept the default Box volume,
|
||
or change it if you prefer to do so.
|
||
|
||
Enter the Vent Frequency in Hertz. Again, since this is your
|
||
first time through, press RETURN to accept the default value.
|
||
PERFECT BOX will now calculate :
|
||
1. Amplitude response in decibels;
|
||
2. Maximum Power in Watts;
|
||
and 3. Maximum Sound Pressure Level, at each frequency cycle
|
||
between 10 and 200 Hertz. (100 Hz in Quick mode.)
|
||
|
||
Please wait ... Calculating data for the frequency of xx Hz.
|
||
|
||
Be patient here. PERFECT BOX is running through a healthy chunk
|
||
of floating point calculations, just sit back, watch the counter
|
||
change and reminisce about the good old slide rule days. When the
|
||
calculations are complete, an Output/Changes Menu will be
|
||
presented. A math coprocessor chip makes this loop fly by in
|
||
about 2 seconds (if you have one installed!)
|
||
|
||
|
||
PERFECT BOX - Version 4.5
|
||
<20>ͺ Output Choices <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ
|
||
<20> <20> <20> Record # : 106 <20>
|
||
<20> (F) Frequency vs. Amplitude <20> <20> Driver : PR 38 XM 150 <20>
|
||
<20> (L) Excursion Limit plot <20> <20> Manufacturer: POLYDAX <20>
|
||
<20> (V) View data points <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
|
||
<20> (U) QUAD-Plot Set-Up [ OFF ] <20>
|
||
<20> (D) Print Data points <20> Quick mode
|
||
<20> (P) Calculate Ports <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Changes <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ
|
||
<20> (W) Driver Worksheet <20> <20>
|
||
<20> <20> (B) Change Box Volume or Vent freq.<2E> <20>=2.857
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> (E) Change EQ. Frequency or D <20> h=1.365
|
||
<20> (A) Change All parameters <20>
|
||
<20> (T) Toggle graphics mode (EGA) <20>
|
||
<20> (C) Change QLoss <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ Done̻
|
||
<20> (Qloss = 7 ) <20> <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> (S) Load/Save Align. <20>
|
||
<20> (R) Retrieve another <20>
|
||
<20> (Q) Quit to DOS <20>
|
||
<20> <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ
|
||
|
||
Use PgUp-PgDn-Home-End- - - <RETURN>= Select - or HotKey
|
||
|
||
Output/Changes Menu
|
||
|
||
OUTPUT CHOICES:
|
||
|
||
(F) Amplitude vs. Frequency Plot
|
||
|
||
This choice will plot the classical Bode (pronounced BO-DEE) or
|
||
Amplitude Response plot. If the Quick mode was on during
|
||
calculations, the plot will stop a 100 Hz. You may print a copy
|
||
of the plot on your graphics printer by pressing a "P". This
|
||
pops up a nice time-date stamp, dumps the plot to your printer.
|
||
After the printer is finished, you can send a Form Feed (FF) to
|
||
your printer by pressing the <F10> function key.
|
||
|
||
(L) Excursion Limit Plot
|
||
|
||
This graph of SPL & Power vs. Frequency, will give you an picture
|
||
of the system driven at maximum power. This plot gives the
|
||
Sound Pressure Level (in dB) and the input power required to
|
||
reach the excursion limit (Xmax) of the driver. See the Design
|
||
Notes chapter of this document for more discussion of this
|
||
important graph.
|
||
|
||
|
||
|
||
(U) QUAD-Plot Setup (New to Version 4.5)
|
||
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ
|
||
<20>Current Data<74>
|
||
<20> in RAM. <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||
<20>Trace toggle Model#: Filename: Load Data:
|
||
<20><><EFBFBD>> F1 On <20><>Ŀ
|
||
<20>
|
||
F2 Off <20><><EFBFBD><EFBFBD>< --- <20>Empty <<3C> F6Ŀ
|
||
<20> <20>
|
||
Press F1-F4 F3 Off <20><><EFBFBD><EFBFBD>< --- <20>Empty <<3C> F7Ĵ
|
||
to enable <20> <20>
|
||
that trace #. F4 Off <20><><EFBFBD><EFBFBD>< --- <20>Empty <<3C> F8Ĵ
|
||
<20> <20>
|
||
<20> <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||
<20>From Disk file.<2E>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||
|
||
Press F10 to Exit
|
||
|
||
Save driver data in the Output Menu with the F7 key.
|
||
You may load up to three data files for display
|
||
in the QUAD Plot mode.
|
||
|
||
|
||
QUAD-Plot Setup Menu
|
||
|
||
For EGA users, the QUAD-Plot function will allow you to compare
|
||
Amplitude Plots from the current run with up to three other runs
|
||
previously saved from the Output Menu with the F7 option.
|
||
|
||
Once in the QUAD-Plot Setup menu, you load the data files with
|
||
function keys F6, F7 and F8. The function keys F1-F4 will toggle
|
||
each trace off and on, allowing printout of fewer traces than the
|
||
loaded number. Once you have loaded your comparison files, press
|
||
F10 to return to the Output Menu. You should notice that the
|
||
prompt beside the QUAD-Plot Setup function should say
|
||
"[ ON ]" This is automatically set to ON after leaving the QUAD-
|
||
Plot Setup Menu. You can toggle the QUAD-Plot OFF/ON with the F4
|
||
key in the Output Menu. Turning OFF the QUAD-Plot will not erase
|
||
the currently loaded data, and will allow you to bounce back and
|
||
forth between the usual plot modes and QUAD-Plot.
|
||
|
||
The QUAD-Plot function is available only in the EGA graphics
|
||
mode. If your machine cannot support EGA 43 line mode, you
|
||
cannot use QUAD-Plot. Also, your mouse becomes useful tool
|
||
during the QUAD-Plot display. Without a mouse, some features
|
||
will be unavailable to you, but you still can view up to four
|
||
graphs at once.
|
||
|
||
|
||
Perfect Box (4.5) <20> QUAD-Plot
|
||
|
||
| Fb
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ
|
||
<20>Registered to:<3A>+6 <20> <20>
|
||
<20> <20> 5 <20> <20>
|
||
<20>Your name or <20> 4 <20> <20>
|
||
<20>Company should<6C> 3 <20> <20>
|
||
<20>be listed <20> 2 <20> <20>
|
||
<20>here. <20> 1 <20> <20>
|
||
<20> <20> 0<><30><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>
|
||
<20> <20>-1 <20> <20>
|
||
<20> <20>-2 <20> <20>
|
||
<20> <20>-3 <20> <20>
|
||
<20> <20>-4 <20> <20>
|
||
<20> <20>-5 <20> <20>
|
||
<20> <20>-6 <20> <20>
|
||
<20> <20>-7 <20> <20>
|
||
<20> <20>-8 <20> <20>
|
||
<20> <20>-9 <20> <20>
|
||
<20> <20>-10<31> <20>
|
||
<20> PERFECT BOX <20>-11<31> <20>
|
||
<20> <20>-12<31> <20>
|
||
<20> by <20>-13<31> <20>
|
||
<20> Warren <20>-14<31> <20>
|
||
<20> A. <20>-15<31><35><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>
|
||
<20> Merkel <20> <20>
|
||
<20> <20> 20 30 40 50 60 7 8 9 100 200 Hz <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ
|
||
<20> <20> <20> <20> <20> <20>
|
||
<20> <20>Trace 1 <20> Trace 2 <20> Trace 3 <20> Trace 4 <20>
|
||
<20>At Magnifier: <20> 3124 <20> Mod: <20> Mod: <20> Mod: <20>
|
||
<20>Amp = <20> ALTEC <20> Man: <20> Man: <20> Man: <20>
|
||
<20>Freq= <20> From RAM <20> File: <20> File: <20> File: <20>
|
||
<20>At Ruler: <20> Vb : 2.79 CF <20> Vb : <20> Vb : <20> Vb : <20>
|
||
<20>Amp = <20> Fb : 33.44 Hz<48> Fb : <20> Fb : <20> Fb : <20>
|
||
<20>Freq= <20> Ord : 4 <20> Ord : <20> Ord : <20> Ord : <20>
|
||
<20> <20> Feq : <20> Feq : <20> Feq : <20> Feq : <20>
|
||
<20> <20> D : <20> D : <20> D : <20> D : <20>
|
||
<20> <20> Single <20> <20> <20> <20>
|
||
<20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
|
||
|
||
Press P to Print <20> <<3C><> to continue
|
||
|
||
The QUAD-Plot Screen (not to scale)
|
||
|
||
Each trace is plotted in a different color and can be temporally
|
||
erased with function keys F1-F4 or with a left click in the data
|
||
area for that particular trace. If you have a mouse, you can use
|
||
the cursor as a magnifier to determine which Trace is where. As
|
||
you pass over a particular trace, a asterisk will flash beside
|
||
that Trace's number.
|
||
|
||
|
||
You can also set a ruler line at any point on the graph with the
|
||
left mouse button. This will allow quick measurements of any
|
||
point on the plot. The ruler will be drawn from the center of
|
||
the magnifier to each axis, and the values for the ruler will be
|
||
locked at the "At Ruler" area. To erase the ruler, click the
|
||
right mouse button. The "At Magnifier" values are constantly
|
||
updated to the cursor magnifier position.
|
||
|
||
You may have to calibrate your mouse to read the plot correctly.
|
||
If the magnifier values do not reflect the actual point on the
|
||
plot, move the magnifier to the words "At Magnifier" and click
|
||
both buttons. You will be asked to move the magnifier to the
|
||
20Hz-0dB point an click the left button. Then you will be asked
|
||
to move the magnifier to adjust the "At Magnifier" values to
|
||
reflect exactly 0dB at 20 Hz. Then click left again. Then, if
|
||
you are satisfied that you correctly positioned the mouse, press
|
||
the right button to save these new calibrated values in the
|
||
Perfect.ctl file. You can abort by pressing the right button.
|
||
|
||
As with the other Plot screens in PERFECT BOX, you can press a
|
||
"P" to print the screen on your graphics printer. The F10 key
|
||
will cause a Form Feed command to be sent to your printer.
|
||
|
||
At this time, only the Amplitude Plots can be compared. If
|
||
sufficent user interest dictates the addition of the SPL-Power
|
||
plots into the QUAD-Plot function, I will work that mode into the
|
||
next release. (Registered users first though...)
|
||
|
||
(V) View data points
|
||
|
||
This option will list on the screen, all calculated data,
|
||
between the frequency limits of your choice.
|
||
|
||
(D) Print data points
|
||
|
||
This option will print on your printer, all calculated data,
|
||
between the frequency limits of your choice.
|
||
|
||
(W) Driver Worksheet
|
||
|
||
This option produces on your printer, a worksheet which
|
||
gives you a handy reference table to use as you change the
|
||
different alignments about your system. Each block can be filled
|
||
from data printed on the Frequency vs. Amplitude plot option. I
|
||
suggest that you do this option first (only if you have a printer
|
||
on-line.) and log each repetition of your progress.
|
||
|
||
(B) Change Box Volume or Vent Frequency
|
||
(E) Change EQ. Frequency or D
|
||
(A) Change ALL parameters
|
||
|
||
At this point you may choose what parameter to change in an
|
||
attempt to optimize the frequency plot, or what ever else you are
|
||
trying to achieve (maximum power for instance.) If you are
|
||
currently working on a 2nd or 4th order system, the "Change
|
||
EQUALIZER Frequency or D." choice will not be allowed. Thus if
|
||
you want to change to an "equalized" order, you must use the
|
||
"Change ALL Parameters" option. Remember that the previous value
|
||
for each prompt in the CHANGE menu, there will be the default
|
||
value (just press RETURN.)
|
||
|
||
(T) Toggle graphics mode
|
||
|
||
This choice toggles you between EGA and CGA modes. This is
|
||
really not needed anymore. I left it in for those of you whom
|
||
can't get the build-in graphics dump program to function properly
|
||
with your printer. You could for example, have the DOS
|
||
GRAPHICS.COM loaded before PB, and switch to CGA for printing.
|
||
|
||
(C) Change Qloss
|
||
|
||
This option allows you to account for box leakage losses. Normal
|
||
vented cabinets are modeled at Ql=7. If you do not have the
|
||
means to accurately measure Qloss, then leave Ql=7.
|
||
|
||
(S) Load/Save Alignment
|
||
|
||
This choice allows you to save your current design parameters to
|
||
the BOXDATA file for future use. This becomes very handy if you
|
||
want to keep track of your best designs for each driver.
|
||
|
||
(R) Retrieve another driver
|
||
|
||
This choice will dump all calculated data, and return you to the
|
||
opening menu.
|
||
|
||
(P) Calculate Ports
|
||
|
||
After you are satisfied with the current design parameters,
|
||
PERFECT BOX will calculate the port lengths required to tune the
|
||
cabinet to the frequency currently chosen. A column for two
|
||
identical length ports is also given. Dual ports are useful when
|
||
the box volume or the MACH speed is too large for a single port.
|
||
The MACH number is the percent of the speed of sound that will
|
||
occur at the largest port output.
|
||
|
||
|
||
POLYDAX PR 38 XM 150
|
||
BOX VOLUME= 8.53 Ft^3 BOX FREQUENCY= 26.61 Hz. ORDER : 4
|
||
HEIGHT= 39.72 in. WIDTH= 24.52 in. DEPTH= 15.2 in.
|
||
|
||
VENT LENGTHS FOR TYPICAL INTERNAL DIAMETERS OF PVC PIPE
|
||
(Inches)
|
||
|
||
|
||
DIAMETER LENGTH MACH DUAL VENTS MACH
|
||
------- ------ ---- ---------- ----
|
||
1 -.38 1.243 NO ! | -.03 .311 NO!
|
||
1.5 -.31 .553 NO ! | .48 .138
|
||
2 -.06 .311 NO ! | 1.35 .078 Best
|
||
2.5 .37 .199 Use Dual| 2.57 .05 Best
|
||
3 .97 .138 O.K. | 4.13 .035 Best
|
||
3.5 1.75 .101 O.K. | 6.05 .025 Best
|
||
4 2.7 .078 Best | 8.32 .019 Best
|
||
4.5 3.83 .061 Best | 10.95 .015 Best
|
||
5 5.13 .05 Best | 13.92 .012
|
||
|
||
Vent Calculations.
|
||
|
||
Stay away from large (speed> 0.2) port MACH speeds as they
|
||
will cause unmusical whistle noises from the port. Ports that
|
||
are longer than the box depth, can be curved inside the enclosure
|
||
with PVC swept elbows.
|
||
|
||
V. DESIGN HINTS:
|
||
|
||
If the ideal box volume is too large to be realistically built,
|
||
PERFECT BOX will allow you to see just how the loudspeaker
|
||
performance will suffer, as you down size box volume. It is do to
|
||
this iterative design process that PERFECT BOX accels other
|
||
modeling programs. By changing either box volume, port
|
||
frequency, or in EQ cases, EQ frequency and boost, a "perfect"
|
||
frequency curve should be obtainable. At this point you can tell
|
||
how good a driver really is because sometimes one driver will
|
||
out perform others in half the enclosure volume.
|
||
|
||
The port frequency is set by the area and length of the vent.
|
||
PERFECT BOX will calculate the port for you, but the length is
|
||
typically 10% off, so add an half-inch to the calculated value,
|
||
and measure the box frequency for yourself. The system will not
|
||
perform as calculated if you miss the port frequency by as little
|
||
as 1 Hz, so try to hit it as close at possible. Also, after you
|
||
have reached a final box size, increase the box volume by as much
|
||
as required to account for volume used by the drivers, bracing,
|
||
and crossover network. It is much better to error on the high
|
||
side of Box Volume. I typically add 10% to the final size as a
|
||
fudge factor. You can always add braces to account for any
|
||
overage.
|
||
|
||
|
||
To find box dimensions from the box volume, take the volume
|
||
in cubic feet, multiply by 1728 cubic in/ft^3, to get in^3. Then
|
||
take the cube root (or raise it to the 0.3333334 th power.) Now
|
||
this number is the width in inches. Multiply the width by 1.62
|
||
for the height, and multiply the width by 0.62 for the depth.
|
||
volume (in^3) = volume (ft^3) * 1728
|
||
width (in.) = (volume (in^3) )^0.3333334
|
||
height (in.) = width * 1.62
|
||
depth (in.) = width * 0.62
|
||
NOTE: All dimensions are internal, not external!
|
||
This will give the box a typical speaker "look" and also set the
|
||
dimensions up for minimum internal reflections. PERFECT BOX
|
||
calculates these dimensions for you and prints them in the port
|
||
length table.
|
||
|
||
|
||
VI. COMMAND LINE SWITCHES
|
||
|
||
There are a few command switches which will override the settings
|
||
in the PERFECT.CTL file.
|
||
|
||
/CGA = Sets graphics mode to CGA.
|
||
/EGA = Sets graphics mode to EGA.
|
||
/HERC = Sets graphics mode to Hercules.
|
||
/LPT1 = Sets the active printer port to LPT1:
|
||
/LPT2 = Sets the active printer port to LPT2:
|
||
/LPT3 = Sets the active printer port to LPT3:
|
||
/QUICK = Runs PB in the fast mode (10-100 Hz).
|
||
/RESETMOUSE = Clears previous mouse calibrations.
|
||
/NOMOUSE = Defeats all mouse functions.
|
||
/PTF = Reroutes all text printing to a file called
|
||
"Printer.out". All text output is APPENDED to this file.
|
||
/NOPAPER = Defeats the printer error checking.
|
||
|
||
This might be useful if you are using a "Print-TO-File" TSR to
|
||
grab output. As it stands now, the Novell "SPOOL" command is
|
||
supported for LPT1: if your workstation has an active local
|
||
printer attached. The /NOPAPER option bypasses local printer
|
||
checking and allows SPOOL to capture LPT1 correctly without a
|
||
local printer attached to LPT1:.
|
||
|
||
All values affected by the Command line switches except /PTF can
|
||
be made the current default by the "W" Write Defaults command in
|
||
the opening menu.
|
||
|
||
NOTE: The /NOTEST switch is no longer supported (or required.)
|
||
|
||
If you have a 8087/80287 coprocessor installed, PB will
|
||
automatically use it for all Floating Point calculations. If for
|
||
some reason, you would like to defeat the coprocessor from
|
||
functioning, set an Environment variable in your CONFIG.SYS file
|
||
|
||
NO87=Coprocessor is Defeated
|
||
|
||
and reboot, before executing Perfect Box. You may also use the
|
||
DOS "SET" command to create the NO87 variable.
|
||
|
||
|
||
|
||
VII. REFERENCES:
|
||
|
||
This document and the program PERFECT BOX are only tools for
|
||
the speaker designer. One must know how to use these tools
|
||
properly before judging the usefulness of PERFECT BOX. I suggest
|
||
that you read or subscribe to any of the following publications
|
||
on the finer art of speaker building.
|
||
|
||
SPEAKER BUILDER MAGAZINE (6 times a year)
|
||
Edward T. Dell, Jr., Publisher
|
||
PO Box 494 Peterborough, NH 03458
|
||
|
||
An excellent publication. Articles vary from the most basic
|
||
"cookbook" projects, to the exotic mathematical theories used in
|
||
PERFECT BOX. Electronic projects and crossover designs are
|
||
covered in depth. Many of the systems discussed are years before
|
||
the designs hit the market. Articles are written by
|
||
knowledgeable authors well known in the field, ideas of which
|
||
have been mimicked by the major Speaker Manufacturers. Now with
|
||
full color layouts, software and book reviews, Speaker Builder is
|
||
an absolute must.
|
||
|
||
|
||
"The Loudspeaker Design Cookbook"
|
||
by Vance Dickason
|
||
Distributed by:
|
||
Old Colony Sound Lab
|
||
PO Box 243
|
||
Peterborough, NH 03458-0243
|
||
|
||
Hats Off! to Dickason for handy reference to all design formulas
|
||
required by the speaker designer. Covers explanations of many
|
||
types of crossover designs and enclosure systems, including Push-
|
||
Pull, and Isobaric.
|
||
|
||
|
||
"How to Design, Build, & Test Complete Speaker Systems"
|
||
by David B. Weems
|
||
Library of Congress #TK9968.W43
|
||
Published by:
|
||
TAB Books
|
||
Blue Ridge Summit, PA 17214
|
||
No. 1064
|
||
|
||
The perfect starter book in speaker design. Written in a down to
|
||
earth style, Weems covers the T/S theories with just enough math
|
||
to get the job done correctly without being overbearing to the
|
||
beginner. Many complete projects and testing methods are
|
||
covered. A beginners standard for the past decade!
|
||
|
||
|
||
|
||
VIII. ERRATA:
|
||
|
||
Your support helps! PERFECT BOX is supported by YOU, the user.
|
||
Without user support, Shareware such as PERFECT BOX cannot
|
||
continue to exist! Use this program!, give a copy of PERFECT BOX
|
||
to your friends (the BBS Archive file is the best way to make
|
||
sure all the PERFECT BOX files are present.) Above all, don't
|
||
forget your part in the deal! If you are using PERFECT BOX on a
|
||
trial basis, that's fine. Determine its usefulness in accurately
|
||
designing your new speaker system, then REGISTER! The money that
|
||
you save by building your own system can easily cover the
|
||
registration fee.
|
||
|
||
If you are using PERFECT BOX in a business or commercial
|
||
environment, you MUST Register, PERIOD. IF YOU ARE MAKING A
|
||
COMMERCIAL PROFIT USING PERFECT BOX WITHOUT REGISTRATION, YOU ARE
|
||
IN VIOLATION OF YOUR SHAREWARE AGREEMENT WITH THIS AUTHOR. Your
|
||
job is easy with PERFECT BOX in your tool kit. Don't forget who
|
||
bought you that tool!
|
||
|
||
Many registered users are using PERFECT BOX for professional
|
||
sound reinforcement or automotive sound applications. If this is
|
||
true for you, just don't forget the concepts under which
|
||
shareware functions. Perfect Box can easily pay for itself with
|
||
ONE SALE.
|
||
|
||
PERFECT BOX is under constant scrutiny for improvement. If you
|
||
have any ideas for new features/functions, or problems in program
|
||
operation, send them to me at the address on the next page.
|
||
Your suggestion could be included in the next revision of PERFECT
|
||
BOX. By registering your copy, you will be sent (if requested) a
|
||
disk with the current Version installed in your name. You will
|
||
also receive a copy of the next MAJOR PERFECT BOX revision, and
|
||
new BOXDATA file parameters. Registered users can have their
|
||
current copy updated at any time. Also, Registered users can
|
||
download the future releases of PERFECT BOX directly from my 24
|
||
hour BBS at FIDONET 363/507 (407-281-5522 : 2400-N-8-1),
|
||
including unlimited "Online support" through BBS E-Mail.
|
||
|
||
If you want to others to share in your BOXDATA resources, please
|
||
send a COPY of your BOXDATA file on disk (5.25" or 3.5") to me
|
||
in a U.S. Post Office approved disk envelope (or safe
|
||
equivalent.) Or, upload your BOXDATA file to my BBS.
|
||
|
||
|
||
TO REGISTER:
|
||
|
||
Send $40.00 in U.S. funds (personal checks accepted) to cover
|
||
registration and return postage. IT'S THAT SIMPLE.
|
||
|
||
The un-registered copy is NOT "crippled" in any way. All PERFECT
|
||
BOX functions are available on the un-registered program.
|
||
|
||
Please make checks payable to:
|
||
|
||
|
||
>>> WARREN A. MERKEL <<
|
||
|
||
|
||
and send your contribution to:
|
||
|
||
Warren A. Merkel
|
||
2851 Newcomb Ct.
|
||
Orlando, FL 32826
|
||
|
||
|
||
(PERFECT BOX 4.5) *** End of Document *** (PERFECT.DOC)
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|